extract: add extract bool and string value functions

This introduces a new state check that extracts an underlying attribute value by traversing the state with tfjsonpath using a specified path.

statecheck/extract_bool_value.go

@@ -0,0 +1,86 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package statecheck
+
+import (
+	"context"
+	"fmt"
+
+	tfjson "github.com/hashicorp/terraform-json"
+	"github.com/hashicorp/terraform-plugin-testing/tfjsonpath"
+)
+
+var _ StateCheck = extractBoolValue{}
+
+type extractBoolValue struct {
+	resourceAddress string
+	attributePath   tfjsonpath.Path
+	targetVar       *bool
+}
+
+func (e extractBoolValue) CheckState(ctx context.Context, req CheckStateRequest, resp *CheckStateResponse) {
+	var resource *tfjson.StateResource
+
+	if req.State == nil {
+		resp.Error = fmt.Errorf("state is nil")
+
+		return
+	}
+
+	if req.State.Values == nil {
+		resp.Error = fmt.Errorf("state does not contain any state values")
+
+		return
+	}
+
+	if req.State.Values.RootModule == nil {
+		resp.Error = fmt.Errorf("state does not contain a root module")
+
+		return
+	}
+
+	for _, r := range req.State.Values.RootModule.Resources {
+		if e.resourceAddress == r.Address {
+			resource = r
+
+			break
+		}
+	}
+
+	if resource == nil {
+		resp.Error = fmt.Errorf("%s - Resource not found in state", e.resourceAddress)
+
+		return
+	}
+
+	result, err := tfjsonpath.Traverse(resource.AttributeValues, e.attributePath)
+	if err != nil {
+		resp.Error = err
+
+		return
+	}
+
+	if result == nil {
+		resp.Error = fmt.Errorf("nil: result for attribute '%s' in '%s'", e.attributePath, e.resourceAddress)
+
+		return
+	}
+
+	switch t := result.(type) {
+	case bool:
+		*e.targetVar = t
+	default:
+		resp.Error = fmt.Errorf("invalid type for attribute '%s' in '%s'. Expected: bool, Got: %T", e.attributePath, e.resourceAddress, t)
+
+		return
+	}
+}
+
+func ExtractBoolValue(resourceAddress string, attributePath tfjsonpath.Path, targetVar *bool) StateCheck {
+	return extractBoolValue{
+		resourceAddress: resourceAddress,
+		attributePath:   attributePath,
+		targetVar:       targetVar,
+	}
+}

statecheck/extract_bool_value_test.go

@@ -0,0 +1,153 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package statecheck_test
+
+import (
+	"fmt"
+	"regexp"
+	"testing"
+
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
+
+	r "github.com/hashicorp/terraform-plugin-testing/helper/resource"
+	"github.com/hashicorp/terraform-plugin-testing/statecheck"
+	"github.com/hashicorp/terraform-plugin-testing/tfjsonpath"
+)
+
+func TestExtractBoolValue_Basic(t *testing.T) {
+	t.Parallel()
+
+	// targetVar will be set to the extracted value.
+	var targetVar bool
+
+	r.Test(t, r.TestCase{
+		ProviderFactories: map[string]func() (*schema.Provider, error){
+			"test": func() (*schema.Provider, error) { //nolint:unparam // required signature
+				return testProvider(), nil
+			},
+		},
+		Steps: []r.TestStep{
+			{
+				Config: `resource "test_resource" "one" {
+					bool_attribute = true
+				}
+				`,
+				ConfigStateChecks: []statecheck.StateCheck{
+					statecheck.ExtractBoolValue(
+						"test_resource.one",
+						tfjsonpath.New("bool_attribute"),
+						&targetVar,
+					),
+				},
+			},
+		},
+	})
+
+	t.Run("CheckTargetVar", func(t *testing.T) {
+		if err := testAccAssertBoolEquals(true, targetVar); err != nil {
+			t.Errorf("Error in testAccAssertBoolEquals: %v", err)
+		}
+	})
+}
+
+func TestExtractBoolValue_KnownValueWrongType(t *testing.T) {
+	t.Parallel()
+
+	// targetVar will be set to the extracted value.
+	var targetVar bool
+
+	r.Test(t, r.TestCase{
+		ProviderFactories: map[string]func() (*schema.Provider, error){
+			"test": func() (*schema.Provider, error) { //nolint:unparam // required signature
+				return testProvider(), nil
+			},
+		},
+		Steps: []r.TestStep{
+			{
+				Config: `resource "test_resource" "one" {
+					float_attribute = 1.23
+				}
+				`,
+				ConfigStateChecks: []statecheck.StateCheck{
+					statecheck.ExtractBoolValue(
+						"test_resource.one",
+						tfjsonpath.New("float_attribute"),
+						&targetVar,
+					),
+				},
+				ExpectError: regexp.MustCompile(`invalid type for attribute \'float_attribute\' in \'test_resource\.one\'. Expected: bool, Got: json\.Number`),
+			},
+		},
+	})
+}
+
+func TestExtractBoolValue_Null(t *testing.T) {
+	t.Parallel()
+
+	// targetVar will be set to the extracted value.
+	var targetVar bool
+
+	r.Test(t, r.TestCase{
+		ProviderFactories: map[string]func() (*schema.Provider, error){
+			"test": func() (*schema.Provider, error) { //nolint:unparam // required signature
+				return testProvider(), nil
+			},
+		},
+		Steps: []r.TestStep{
+			{
+				Config: `resource "test_resource" "one" {
+					bool_attribute = null
+				}
+				`,
+				ConfigStateChecks: []statecheck.StateCheck{
+					statecheck.ExtractBoolValue(
+						"test_resource.one",
+						tfjsonpath.New("bool_attribute"),
+						&targetVar,
+					),
+				},
+				ExpectError: regexp.MustCompile(`nil: result for attribute \'bool_attribute\' in \'test_resource.one\'`),
+			},
+		},
+	})
+}
+
+func TestExtractBoolValue_ResourceNotFound(t *testing.T) {
+	t.Parallel()
+
+	// targetVar will be set to the extracted value.
+	var targetVar bool
+
+	r.Test(t, r.TestCase{
+		ProviderFactories: map[string]func() (*schema.Provider, error){
+			"test": func() (*schema.Provider, error) { //nolint:unparam // required signature
+				return testProvider(), nil
+			},
+		},
+		Steps: []r.TestStep{
+			{
+				Config: `resource "test_resource" "one" {
+					bool_attribute = true
+				}
+				`,
+				ConfigStateChecks: []statecheck.StateCheck{
+					statecheck.ExtractBoolValue(
+						"test_resource.two",
+						tfjsonpath.New("bool_attribute"),
+						&targetVar,
+					),
+				},
+				ExpectError: regexp.MustCompile("test_resource.two - Resource not found in state"),
+			},
+		},
+	})
+}
+
+// testAccAssertBoolEquals compares the expected and target bool values.
+func testAccAssertBoolEquals(expected bool, targetVar bool) error {
+	if targetVar != expected {
+		return fmt.Errorf("expected targetVar to be %v, got %v", expected, targetVar)
+	}
+	return nil
+}

statecheck/extract_string_value.go

@@ -0,0 +1,87 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package statecheck
+
+import (
+	"context"
+	"fmt"
+
+	tfjson "github.com/hashicorp/terraform-json"
+	"github.com/hashicorp/terraform-plugin-testing/tfjsonpath"
+)
+
+var _ StateCheck = extractStringValue{}
+
+type extractStringValue struct {
+	resourceAddress string
+	attributePath   tfjsonpath.Path
+	targetVar       *string
+}
+
+func (e extractStringValue) CheckState(ctx context.Context, req CheckStateRequest, resp *CheckStateResponse) {
+	var resource *tfjson.StateResource
+
+	if req.State == nil {
+		resp.Error = fmt.Errorf("state is nil")
+
+		return
+	}
+
+	if req.State.Values == nil {
+		resp.Error = fmt.Errorf("state does not contain any state values")
+
+		return
+	}
+
+	if req.State.Values.RootModule == nil {
+		resp.Error = fmt.Errorf("state does not contain a root module")
+
+		return
+	}
+
+	for _, r := range req.State.Values.RootModule.Resources {
+		if e.resourceAddress == r.Address {
+			resource = r
+
+			break
+		}
+	}
+
+	if resource == nil {
+		resp.Error = fmt.Errorf("%s - Resource not found in state", e.resourceAddress)
+
+		return
+	}
+
+	result, err := tfjsonpath.Traverse(resource.AttributeValues, e.attributePath)
+	if err != nil {
+		resp.Error = err
+
+		return
+	}
+
+	if result == nil {
+		resp.Error = fmt.Errorf("nil: result for attribute '%s' in '%s'", e.attributePath, e.resourceAddress)
+
+		return
+	}
+
+	switch t := result.(type) {
+	case string:
+		*e.targetVar = t
+		return
+	default:
+		resp.Error = fmt.Errorf("invalid type for attribute '%s' in '%s'. Expected: string, Got: %T", e.attributePath, e.resourceAddress, t)
+
+		return
+	}
+}
+
+func ExtractStringValue(resourceAddress string, attributePath tfjsonpath.Path, targetVar *string) StateCheck {
+	return extractStringValue{
+		resourceAddress: resourceAddress,
+		attributePath:   attributePath,
+		targetVar:       targetVar,
+	}
+}

statecheck/extract_string_value_test.go

@@ -0,0 +1,59 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package statecheck_test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
+
+	r "github.com/hashicorp/terraform-plugin-testing/helper/resource"
+	"github.com/hashicorp/terraform-plugin-testing/statecheck"
+	"github.com/hashicorp/terraform-plugin-testing/tfjsonpath"
+)
+
+func TestExtractStringValue_Basic(t *testing.T) {
+	t.Parallel()
+
+	// targetVar will be set to the extracted value.
+	var targetVar string
+
+	r.Test(t, r.TestCase{
+		ProviderFactories: map[string]func() (*schema.Provider, error){
+			"test": func() (*schema.Provider, error) { //nolint:unparam // required signature
+				return testProvider(), nil
+			},
+		},
+		Steps: []r.TestStep{
+			{
+				Config: `resource "test_resource" "one" {
+					string_attribute = "str"
+				}
+				`,
+				ConfigStateChecks: []statecheck.StateCheck{
+					statecheck.ExtractStringValue(
+						"test_resource.one",
+						tfjsonpath.New("string_attribute"),
+						&targetVar,
+					),
+				},
+			},
+		},
+	})
+
+	t.Run("CheckTargetVar", func(t *testing.T) {
+		if err := testAccAssertStringEquals("str", targetVar); err != nil {
+			t.Errorf("Error in testAccAssertBoolEquals: %v", err)
+		}
+	})
+}
+
+// testAccAssertStringEquals compares the expected and target string values.
+func testAccAssertStringEquals(expected string, targetVar string) error {
+	if targetVar != expected {
+		return fmt.Errorf("expected targetVar to be %v, got %v", expected, targetVar)
+	}
+	return nil
+}